/*!
 * Thumbnail helper for fancyBox
 * version: 1.0.7 (Mon, 01 Oct 2012)
 * @requires fancyBox v2.0 or later
 *
 * Usage:
 *     $(".fancybox").fancybox({
 *         helpers : {
 *             thumbs: {
 *                 width  : 50,
 *                 height : 50
 *             }
 *         }
 *     });
 *
 */
(function ($) {
    //Shortcut for fancyBox object
    var F = $.fancybox;

    //Add helper object
    F.helpers.thumbs = {
        defaults: {
            width: 50, // thumbnail width
            height: 50, // thumbnail height
            position: 'bottom', // 'top' or 'bottom'
            source: function (item) {  // function to obtain the URL of the thumbnail image
                var href;

                if (item.element) {
                    href = $(item.element).find('img').attr('src');
                }

                if (!href && item.type === 'image' && item.href) {
                    href = item.href;
                }

                return href;
            }
        },
        wrap: null,
        list: null,
        width: 0,
        init: function (opts, obj) {
            var that = this,
                    list,
                    thumbWidth = opts.width,
                    thumbHeight = opts.height,
                    thumbSource = opts.source;

            //Build list structure
            list = '';

            for (var n = 0; n < obj.group.length; n++) {
                list += '<li><a style="width:' + thumbWidth + 'px;height:' + thumbHeight + 'px;" href="javascript:jQuery.fancybox.jumpto(' + n + ');"></a></li>';
            }

            this.wrap = $('<div id="fancybox-thumbs"></div>').addClass(opts.position).appendTo('body');
            this.list = $('<ul>' + list + '</ul>').appendTo(this.wrap);

            //Load each thumbnail
            $.each(obj.group, function (i) {
                var href = thumbSource(obj.group[ i ]);

                if (!href) {
                    return;
                }

                $("<img />").load(function () {
                    var width = this.width,
                            height = this.height,
                            widthRatio, heightRatio, parent;

                    if (!that.list || !width || !height) {
                        return;
                    }

                    //Calculate thumbnail width/height and center it
                    widthRatio = width / thumbWidth;
                    heightRatio = height / thumbHeight;

                    parent = that.list.children().eq(i).find('a');

                    if (widthRatio >= 1 && heightRatio >= 1) {
                        if (widthRatio > heightRatio) {
                            width = Math.floor(width / heightRatio);
                            height = thumbHeight;

                        } else {
                            width = thumbWidth;
                            height = Math.floor(height / widthRatio);
                        }
                    }

                    $(this).css({
                        width: width,
                        height: height,
                        top: Math.floor(thumbHeight / 2 - height / 2),
                        left: Math.floor(thumbWidth / 2 - width / 2)
                    });

                    parent.width(thumbWidth).height(thumbHeight);

                    $(this).hide().appendTo(parent).fadeIn(300);

                }).attr('src', href);
            });

            //Set initial width
            this.width = this.list.children().eq(0).outerWidth(true);

            this.list.width(this.width * (obj.group.length + 1)).css('left', Math.floor($(window).width() * 0.5 - (obj.index * this.width + this.width * 0.5)));
        },
        beforeLoad: function (opts, obj) {
            //Remove self if gallery do not have at least two items
            if (obj.group.length < 2) {
                obj.helpers.thumbs = false;

                return;
            }

            //Increase bottom margin to give space for thumbs
            obj.margin[ opts.position === 'top' ? 0 : 2 ] += ((opts.height) + 15);
        },
        afterShow: function (opts, obj) {
            //Check if exists and create or update list
            if (this.list) {
                this.onUpdate(opts, obj);

            } else {
                this.init(opts, obj);
            }

            //Set active element
            this.list.children().removeClass('active').eq(obj.index).addClass('active');
        },
        //Center list
        onUpdate: function (opts, obj) {
            if (this.list) {
                this.list.stop(true).animate({
                    'left': Math.floor($(window).width() * 0.5 - (obj.index * this.width + this.width * 0.5))
                }, 150);
            }
        },
        beforeClose: function () {
            if (this.wrap) {
                this.wrap.remove();
            }

            this.wrap = null;
            this.list = null;
            this.width = 0;
        }
    }

}(jQuery));